Creating a DNA helix-themed outdoor plant box is a fantastic way to blend science and nature in your garden. To achieve this unique design, selecting plants that naturally grow in spirals or have twisting forms is key. Here are some of the best plants to consider:

1. Corkscrew Hazel (Corylus avellana 'Contorta') – Known for its twisted branches, this shrub adds a dramatic spiral effect, perfect for mimicking DNA’s double helix.

2. Spiral Aloe (Aloe polyphylla) – This succulent forms a stunning spiral pattern, making it an eye-catching centerpiece for your plant box.

3. Twisted Willow (Salix matsudana 'Tortuosa') – With its contorted branches, this tree adds height and a whimsical twist to your design.

4. Corkscrew Rush (Juncus effusus 'Spiralis') – This grass-like plant grows in tight spirals, ideal for filling gaps and enhancing the helix theme.

5. Spiral Ginger (Costus barbatus) – Its coiled flower spikes and lush foliage bring a tropical vibe to your DNA-inspired garden.

For a cohesive look, arrange these plants in pairs or alternating patterns to emulate the double helix structure. Pair them with climbing vines like English Ivy (Hedera helix) for added texture and vertical interest.

Maintenance tips: Ensure proper spacing for growth, use well-draining soil, and provide adequate sunlight based on each plant’s needs. With these selections, your DNA helix-themed plant box will be a conversation starter and a stunning garden feature!